Engines, including compression-ignition engines, spark-ignition engines, gasoline engines, gaseous fuel-powered engines, and other internal combustion engines, may operate more effectively with fuel from which contaminates have been removed prior to the fuel reaching a combustion chamber of the engine. In particular, fuel contaminates, if not removed, may lead to undesirable operation of the engine and/or may increase the wear rate of engine components, such as, for example, fuel system components.
Effective removal of contaminates from the fuel system of a compression-ignition engine may be particularly important. In some compression-ignition engines, air is compressed in a combustion chamber, thereby increasing the temperature and pressure of the air, such that when fuel is supplied to the combustion chamber, the fuel and air mixture ignite. If water and/or other contaminates, such as particulates, are not removed from the fuel, the contaminates may interfere with and/or damage, for example, fuel injectors, which may have orifices manufactured to exacting tolerances and shapes for improving the efficiency of combustion and/or reducing undesirable exhaust emissions. Moreover, the presence of water in the fuel system may cause considerable engine damage and/or corrosion in the injection system.
Fuel filtration systems serve to remove contaminates from the fuel. For example, some conventional fuel systems may include a fuel filter, which removes water and large particulate matter, and another fuel filter, which removes a significant portion of remaining particulate matter (e.g., smaller contaminates), such as fine particulate matter. However, water may be particularly difficult to separate from fuel under certain circumstances. For example, if water is emulsified in the fuel it may be relatively more difficult to separate from fuel. In addition, for some types of fuel, such as, for example, fuel having a bio-component, it may be relatively more difficult to separate the water from the fuel. Therefore, it may be desirable to provide a filter element and/or filter assembly with an improved ability to separate water from fuel.
In addition, when contaminates accumulate in a filter assembly, in order to refresh the effectiveness of the filter assembly, it may be desirable to remove the contaminates from the filter element or replace the filter element of the filter assembly. Removal of the filter element from the filter assembly may result in a void in the fluid system being filtered. As a result, it may be desirable to prime the refreshed filter assembly following assembly of the cleaned filter element or new filter element into the filter assembly by adding some of the fluid from the fluid system to the refreshed filter assembly. However, if unfiltered fluid is taken from the fluid system and added to the filter assembly, the unfiltered fluid must be added to the filter assembly in such a way that the added fluid is filtered by the filter assembly before returning to the fluid system. Thus, it may be desirable to provide a filter element that insures that the fluid added for priming the filter assembly is filtered before it is pumped back into the fluid system.
An attempt to provide desired filtration is described in U.S. Pat. No. 5,084,170 (“the '170 patent”) to Janik et al., issued Jan. 28, 1992. Specifically, the '170 patent discloses a fuel filter assembly having a base that mounts a disposable filter element cartridge. The cartridge includes a dual stage filter system, wherein fuel flows axially to a primary filter element for removing particulate matter and coalescing water droplets, and axially to a secondary filter stage that functions as a water barrier. The filtered fuel flows axially and exits through an outlet passage in the base. Water may be collected in a sump.
Although the fuel filter of the '170 patent purports to separate water from fuel, it may not provide sufficient separation under circumstances where the fuel is emulsified or includes bio-components. Thus, it may not provide a desirable level of fuel filtration. In addition, the fuel filter of the '170 patent does not address possible drawbacks associated with priming the filter element cartridge when servicing or replacing the cartridge.
The filter element and filter assembly disclosed herein may be directed to mitigating or overcoming one or more of the possible drawbacks set forth above.